About Us

Nebulabio is a global leader in in vitro antibody discovery, providing a comprehensive suite of services built upon one of the industry's most extensive and well-characterized collections of premade antibody libraries. Our platform is designed for researchers and developers who require speed, reliability, and proven success without the time and resource investment of custom library construction. With over a decade of experience in library design, curation, and screening optimization, we have empowered hundreds of discovery campaigns against a vast array of target classes—from soluble proteins and peptides to complex membrane antigens and viral epitopes. Our mission is to deliver high-affinity, functional leads in weeks, not months, by leveraging the power of our premade libraries combined with our expert screening execution.

☞Introduction to Premade Antibody Library Screening

Premade Antibody Library Screening is a powerful, accelerated approach to antibody discovery that utilizes pre-constructed, highly diverse phage display libraries as the starting material for biopanning campaigns. Unlike custom library projects that begin with immunization or gene synthesis, this service bypasses the initial 2-3 month construction phase, allowing clients to initiate screening against their target immediately.

The core principle remains the proven phage display technology: antibody fragments (scFv, Fab, or VHH) are displayed on the surface of bacteriophages, with each phage particle carrying the gene encoding its displayed antibody. Through iterative rounds of biopanning—binding to the target, washing away non-binders, eluting specific binders, and amplifying them—the library of billions is rapidly enriched for high-affinity, specific clones. Our service excels by applying this robust selection process to libraries that have been pre-optimized for diversity, functionality, and screening performance. Each of our premade libraries comes with a comprehensive Certificate of Analysis, detailing its size, diversity profile (via NGS), and successful panning history against benchmark antigens, ensuring you start with a proven discovery engine.

☞Classification of Our Premade Antibody Libraries

We offer a curated portfolio of premade libraries, allowing you to select the optimal repertoire for your target biology and desired antibody format.

 By Antibody Format: 

• Premade scFv Libraries: Our most versatile collection, featuring fully human naïve scFv libraries with >10¹⁰ diversity. Ideal for general purpose discovery, CAR-T binder identification, and applications requiring a small, single-gene format.

• Premade Fab Libraries: Human naïve Fab libraries that preserve the natural heterodimeric structure of antibodies. Excellent for projects where lead stability and straightforward conversion to full IgG are priorities.

• Premade VHH (Nanobody) Libraries: Derived from immunized camelids or designed synthetically. These libraries are premier choices for targets requiring exceptional stability, deep cavity binding, or development of imaging agents and intracellular tools.

 By Source & Design: 

• Naïve Libraries: Sourced from non-immunized human donors or animals. They offer universal, unbiased diversity against any antigen, making them the first choice for novel targets.

• Immune Libraries: Generated from hosts immunized with specific antigen classes (e.g., GPCR peptides, viral proteins, tumor lysates). These provide a head start, with repertoires pre-enriched for relevant binders.

• Synthetic Libraries: Rationally designed with tailored diversity in the CDR regions of optimized human frameworks. These offer fully humanized content and can be biased toward specific chemical properties or developability profiles.

☞Library Construction & Screening Process

Our premade libraries are the product of a meticulous, multi-stage development process, ensuring they are fit-for-purpose for high-performance screening.

Development Phase: Library Construction & Validation

1. Design & Sourcing: For naïve libraries, B-cells are ethically sourced from large, diverse donor pools. For immune libraries, immunization protocols are optimized for maximum and diverse response.

2. High-Diversity Cloning: Antibody genes are amplified and cloned into high-efficiency phage display vectors using optimized protocols to maximize library size and minimize bias.

3. Rigorous QC & Validation: Each library batch undergoes exhaustive quality control:

• Titering to confirm library size (>10¹⁰ individual clones).

• Next-Generation Sequencing (NGS) to map the diversity, V-gene usage, and CDR3 length distribution.

• Functional Validation through successful panning against standard control antigens to confirm the library's ability to yield high-affinity binders.

 Screening Phase: The Biopanning Workflow 

Once a library is selected, it enters the standard, yet highly optimized, screening pipeline:

• Antigen Presentation: Your target is immobilized in the optimal format for panning.

• Iterative Selection: The premade library undergoes 3-4 rounds of binding, stringent washing, elution, and amplification.

• Hit Identification: Enriched outputs are plated, and hundreds of individual clones are screened via monoclonal phage ELISA.

• Lead Characterization: Positive clones are sequenced and analyzed. Unique leads are expressed as soluble proteins for affinity and specificity validation.

Figure 1.Schematic diagram of monoclonal antibody generation from sampling to isolation of antibodies. 

☞Our Premade Library Screening Service Workflow

Our service is designed for simplicity, transparency, and efficiency, providing a turnkey solution from target to lead.

Step 1: Library Selection & Project Kick-off

We consult with you to understand your target and goals, then recommend the most appropriate premade library from our portfolio. A project plan with timeline and deliverables is established.

Step 2: Antigen Preparation & Protocol Design

You provide the purified antigen. Our scientists design a customized panning protocol, selecting the best immobilization method (coating, biotinylation) and defining stringency conditions.

Step 3: High-Efficiency Panning Execution

Using the selected premade library, we execute the biopanning campaign in our dedicated labs. We monitor enrichment after each round and provide interim data reports.

Step 4: High-Throughput Clone Analysis

We screen typically 200-500 individual clones from the final round. All ELISA-positive clones are sequenced, and our bioinformatics team clusters the sequences to identify unique lead families.

Step 5: Soluble Expression & Primary Validation

Genes for the top unique leads are subcloned for soluble expression. Purified antibodies are tested in:

• Binding ELISA for confirmation.

• Affinity Measurement using Biolayer Interferometry (Octet).

• Specificity/Cross-reactivity assessment.

Step 6: Final Delivery & Reporting

You receive a comprehensive project report, all sequencing data, expression plasmids for leads, and optional purified antibody samples. We present the data and discuss the recommended path forward.

 Our Service Process Flowchart: 

☞Advantages of Our Premade Library Screening Service

Choosing Nebulabio’s premade library screening service offers distinct strategic and operational benefits:

• Unmatched Speed to Leads: Eliminate the 2-4 months required for library screening. Projects can often be initiated within days of antigen receipt, with deliverable leads in as little as 8-10 weeks.

• Proven Library Quality & Performance: Every library is pre-validated with NGS and functional panning data. You start with a known, high-performance reagent, significantly de-risking the discovery phase compared to an unproven custom library.

• Cost-Effectiveness: By amortizing the significant cost of library construction across multiple clients, we offer a highly competitive service fee, providing access to billion-clone diversity without the upfront capital investment.

• Access to Unmatched Diversity: Our libraries are built from very large donor pools or sophisticated synthetic designs, offering diversity that is often logistically or financially prohibitive for a single custom project.

• Expert Screening Optimization: Our protocols are specifically optimized for each library in our portfolio. This deep familiarity ensures the highest possible screening efficiency and success rate for your target.

• Flexibility and Scalability: Perfect for screening multiple targets or antigen variants in parallel. The service is easily scalable, supporting everything from early feasibility studies to full-scale lead discovery campaigns.

Accelerate your project timeline and leverage proven diversity. Contact us to select the ideal premade library and launch your accelerated path to high-quality antibody leads.